The man was one of my university lecturers, the professor of mathematics Chris Zeeman. Every lecture he gave at Warwick University, where I studied for my first degree, it was a privilege to be there. He had this gift of developing an argument so clearly and logically that every step was obvious and inevitable, and yet again and again he would lead you over a cliff. There would be a gasp from the audience, and Zeeman would pause and twinkle. He showed that complex processes can have simple explanations, and that there is a beauty in these explanations. Mathematicians appreciate this beauty, but so do we all, given the chance.

The book was The Logic of Scientific Discovery, by the philosopher Karl Popper, which had the same combination of clarity of thought with passion. As Popper says: ‘Bold ideas, unjustified anticipations, and speculative thought are our only means for interpreting nature: our only organon, our only instrument for grasping her. And we must hazard them to win our prize. Those among us who are unwilling to expose their ideas to the hazard of refutation do not take part in the scientific game.’ This is the game that I wanted to play.